Ice cream and similar frozen dessert items are packaged in a semi-frozen state in which the product has sufficient fluidity to flow and conform to the carton. During hard freezing of the product to the state the customer normally associates with product of this type, the ice cream tends to form rather firm bonds to the various interior surfaces of the paperboard carton in which it is packaged. Prior art cartons have a variety of designs of tear strips. One carton incorporates into its design both a tear strip, and a release film on the interior of the top cover panel, and underlying the tear strip, to improve the characteristic release of the top cover panel from the contents when the top cover panel is opened to expose the product. In that carton, the release film is released from the tear strip when the tear strip is removed.
In actual practice, paperboard tear strips such as those shown in the prior art have presented substantial difficulty to both the carton manufacturer and the carton user. The paperboard carton manufacturer desirably makes the lines of weakness on the tear strip as strong as possible so that they survive the manufacturing process without tearing. The carton user desires the lines of weakness on the tear strip to be as weak as possible, to assure easy and complete tearing along the entire length of the tear strip.
In cartons of the prior art, the result is a compromise. The lines of weakness are made strong enough to satisfy manufacturing needs, and desirably weak enough to satisfy the customer. Sadly, the number of paperboard tear strips that fail to operate properly is unacceptably high. Those which are too weak, fail in the manufacturer's factory and are discarded. Those which are too strong typically are not detected until the user finds that they fail to tear along the entire length of the tear strip when the carton is first opened. It is not uncommon for the tear strip to properly initiate the tear along the lines of weakness, and then fail internally, leaving part of the tear strip intact on the carton.
It is an object of this invention to provide improved opening means for paperboard packaging structure.
It is a further object to provide a tear strip which is easily manufactured in such a configuration that the tear strip reliably tears along its entire length.